A lightning strike probably set a house on fire in Northern Ireland, the fire service said.

Paul Reilly, 44, was in the red brick property with his father, his son aged 14 and daughter aged 10. They escaped injury.

The Northern Ireland Fire and Rescue Service (NIFRS) said lightning was the probable cause of the blaze at Kingfield Avenue in Downpatrick, Co Down, which badly damaged the roof and filled rooms with acrid smoke.

Mr Reilly discovered two fires, one in the eaves of the roof and a much larger one in the living room.

He recalled: "I ran downstairs to see if I could get a small fire extinguisher to put the (roof) fire out and as I was passing I noticed and heard crackling and noise in the living room just down below where the fire was upstairs and it was engulfed in flames. The whole curtain and TV and that side where the sockets were.

"At that point I knew there was nothing we could do, there was no point in trying to put the wee fire out upstairs, so we just got the family out and raised the alarm."

Mr Reilly said his daughter was petrified after a clap of thunder awakened the family at around 6am.

"There was an almighty bang and I could see there was a big flash outside and sparks and I thought maybe a lamp post or car had been hit.

"She was very frightened at that stage and screaming and I tried to reassure her."

After he discovered the extent of the fire he realised his phone had been "fried" by the lightning strike, the electric was out and the neighbours were all in the same boat.

He went into his son's room.

"There was thick acrid smoke, you could not breathe in it, you could not see in it, it was dark, it was just so dense."

He managed to reach a telephone down the road and the fire service was there within minutes.

Mr Reilly said: "We are just very thankful that we are only talking about bricks and mortar being damaged and there was no loss of life.

"We are shaken up but feeling very thankful at the same time."

He said they had nowhere to stay but family and friends would look after them.

"Short term, we will be fine. Long-term this is not going to be fixed in a couple of days so we are looking at maybe getting somewhere close by and try and get a bit of normality back and a bit of routine."

The house next door had also been damaged.

A fire service spokesman said: " Northern Ireland Fire & Rescue Service finished at the scene at 7.46am and following a fire investigation firefighters have confirmed the probable cause of the fire was lightning."